Examples of viral, fungal and bacterial eye infections include:
Pink eye, or conjunctivitis. Conjunctivitis, also called "pink eye," is a common, highly contagious eye infection that often is spread among children in day care centers, classrooms and similar environments. Teachers and day care workers also are at increased risk of pink eye when they work in close quarters with young children.
Common infectious conjunctivitis types often have viral or bacterial origins. Infants also can acquire conjunctival eye infections (gonococcal and chlamydial conjunctivitis) during birth when a mother has a sexually transmitted disease.
Other viral eye infections (viral keratitis). Besides common pink eye, other viral eye infections include ocular herpes, which occurs with exposure to the Herpes simplex virus.
Fungal keratitis. This type of eye infection made worldwide news in 2006 when a contact lens solution now withdrawn from the market was linked to an outbreak among contact lens wearers.
The fungal eye infection was associated with Fusarium fungi, commonly found in organic matter. This and other fungi can invade the eye in other ways, such as through a penetrating injury caused by a tree branch.
Acanthamoeba keratitis. Contact lens wearers are at increased risk of encountering parasites that can invade the eye and cause a serious sight-threatening infection called Acanthamoeba keratitis. This is why contact lens wearers should observe certain safety tips, such as avoiding swimming while wearing contacts
If you do wear contact lenses when swimming or relaxing in a hot tub, make sure you remove and disinfect your lenses immediately afterward.
Indeed, there is an increased risk of fungal and bacterial eye infections among contact lens wearers in general, and proper contact lens care must be followed.
FDA guidelines recommend that manufacturers include a discard date (not just a date of expiration) on contact lens cleaning and disinfecting products to help minimize the risk of eye infection.
While uncommon in the United States, an eye infection known as trachoma, related to Chlamydia trachomatis, is so widespread in certain under-developed regions that it is a leading cause of blindness. Flies can spread the infection in unsanitary environments, and reinfection is a common problem.
Trachoma typically infects the inner eyelid, which begins to scar. Scarring then causes an "in-turning" of the eyelid, and eyelashes begin to brush against and destroy tissue on the cornea, with resulting permanent blindness.
Good hygiene and availability of treatments such as oral antibiotics are essential to controlling trachoma.
When an eye infection penetrates the eye's interior, as with bacterial endophthalmitis, blindness could result without immediate treatment, often with potent antibiotics. This type of infection can occur with a penetrating eye injury or as a rare complication of eye surgery such as cataract surgery. Any time the eye's globe is penetrated and injured significantly, there is a 4 to 8 percent risk of endophthalmitis.*
Mold that penetrates the eye's interior also can cause endophthalmitis, though rarely, with most cases reported in tropical regions.
Picture 2: Endogenous fungal endophthalmitis in immunocompromised patient